This invention relates to a fan assembly, particularly to a fan assembly of the type which has a housing having side walls, a fan having rotating blades mounted within the housing and a slidable fan screen mounted relative to the housing and spaced from the rotating blades.
In the fan industry, there is a need for a fan housing which allows ready access to the fan unit within the housing for cleaning and maintenance purposes. While being readily accessible for cleaning and maintenance purposes, the fan housing must allow a maximum amount of the air flow through the fan while still providing a safety guard which prevents objects from getting into the path of the fan blades.
A primary concern of the fan industry is safety. During typical fan operation, fan blades am rotated at high RPM's. These rotating fan blades are often enclosed within a fan housing which contains front and rear guards (typically made of wire) in order to limit access to the fan blades during fan operation. Circulating fans are often installed in industrial or agricultural applications, which are notoriously unclean environments. In these types of applications, fans are wall mounted to exhaust air or ceiling hung for providing ventilation to livestock. In these harsh environments, hay, straw, dust, chicken feathers, or other airborne material typically become lodged within the fan housing. Therefor, the fan housing must allow easy access to the fan unit for cleaning and maintenance.
In the past, fans for these applications have had fan housings which include rear and front shielded fan guard faces, with totally or partially shielded side walls. The shielded rear and front fan guard faces will permit some objects to pass partially therethrough. A totally or partially enclosed circumferential side wall connects the rear and front guard faces to enclose the fan blades. The fan blades may be located approximately equal distances from the front and back guard faces, with the guard faces being far enough away from the fan blades to prohibit a human hand from reaching the blade path.
The front and rear fan guards of these devices have been limited to guards that are secured to the fan housing side wall by methods which require the use of tools for removing the guards for access to the fan units for cleaning and maintenance purposes. The methods of securing the front or rear fan guard to the fan housing side wall typically consists of a bolted or screw connection, or even a permanent welded connection of the fan guard to the fan housing side wall.
Since the fan guards are fixedly secured to the fan housing, tools such as screwdrivers and wrenches: and excessive handling is required to open the fan for cleaning and maintenance purposes. As mentioned, these fans are often located in harsh environments, where hay, straw, dust, chicken feathers, or other airborne material typically become lodged within the fan housing. Regular maintenance and cleaning or these fans to remove such material is required to keep these fans operating at maximum efficiency. Since several fans are usually located within a single barn or shed, the removal of the fan guards for cleaning or maintenance purposes becomes labor intensive and time consuming.